Virtual reality experiences are becoming prominent. For example, 360° video is emerging as a new way of experiencing immersive video due to the ready availability of powerful handheld devices such as smartphones. 360° video enables immersive “real life”, “being there” experience for consumers by capturing the 360° degree view of the world. Users can interactively change their viewpoint and dynamically view any part of the captured scene they desire. Display and navigation sensors track head movement in real-time to determine the region of the 360° video that the user wants to view.
Social media sites allow for sharing of personalized video experiences. For example, users share and watch 12 billion minutes of gameplay capture video per month. The videos that are shared are screen captures of the player's view. Different users might like to view different parts of 360° video and might want to share their personalized viewpoints with friends and family. Thus, there is a need for efficiently sharing a user's viewpoint with other users.
Personalized video experiences can be shared by sharing user viewpoint trajectories or user specified region of interests (ROI). A single viewport/ROI trajectory consists of a sequence of viewports/ROIs, one viewport/ROI for every frame of video. There can be multiple viewport/ROI trajectories for a given 360 degrees video—the number of viewport/ROI trajectories depends on the number of users who view the 360 degrees video and want to share their personalized viewport/ROI trajectory. This number could easily reach multiple of hundreds or thousands. So efficient mechanisms for sharing of viewport/ROI trajectories are needed.